I don't understand @fiatjaf's argument here, at least, I don't understand the *strength* of it ("NEVER") ? First, on "global feed", it's a bit like (a more extreme version of) "the mempool" - in a decentralized system there is no single synchronized global state, but .. there can be pockets of smaller synchronized state, at the relay level .. I guess even at the client level? If you have instant access to 10k or 100k messages your client can present them how it wants. I admit to not knowing much of anything about relays, so tell me if I'm wrong. If the answer involves "it's more expensive", remember it can be paid for; I already pay for relays, it's completely normal. Also, it has always been very obvious to me that the "social media" application of nostr would obviously benefit from algorithms for feeds. (though such a thing wouldn't magically make nostr suddenly popular).
Discussion
The point is (i think) the platform server is this coherent database of 'all the things' (which is a lie, because its not all the things on the internet etc.etc.).
This means that there is a known state (i.e. 'global'), and subsequently a perspective on that state (the feed). Choosing your algo is therefor a differing perspective on the same thing.
In Nostr, gathering all the events is just as much a part of the process as the filtering is
Also, things like views, like counts, how long the tracked eyeball stated at the titty etc, is a different ballgame with Nostr